JAK2/STAT3 inhibition attenuates intestinal ischemia-reperfusion injury via promoting autophagy: in vitro and in vivo study.

Background: Intestinal ischemia-reperfusion (I/R) causes severe injury to the intestine, leading to systemic inflammation and multiple organ failure. Autophagy is a stress-response mechanism that can protect against I/R injury by removing damaged organelles and toxic protein aggregates. Recent evidence has identified JAK-STAT signaling pathway as a new regulator of autophagy process, however, their regulatory relationship in intestinal I/R remains unknown.

Methods And Results: We systematically analyzed intestinal transcriptome data and found that JAK-STAT pathway was largely activated in response to I/R with most significant upregulation observed for JAK2 and STAT3. ChIP-Seq and luciferase assays in an in vitro oxygen-glucose deprivation and reoxygenation model revealed that activated JAK2/STAT3 signaling directly inhibited the transcription of autophagy regulator Beclin-1, leading to the suppression of autophagy and the activation of intestinal cell death. These findings were further confirmed in an in vivo mouse model, in which, intestinal I/R injury was associated with the activation of JAK2/STAT3 pathway and the deactivation of Beclin-1-mediated autophagy, while inhibiting JAK2/STAT3 with AG490 reactivated autophagy and improved survival after intestinal I/R injury.

Conclusions: JAK2/STAT3 signaling suppresses autophagy process during intestinal I/R, while inhibiting JAK-STAT can be protective against intestinal I/R injury by activating autophagy. These findings expand our knowledge on intestinal I/R injury and provide therapeutic targets for clinical treatment.